By NEIL A. LEWIS

Published: July 17, 2008

President Bush has invoked executive privilege to block the Justice Department from providing a House panel with material about Vice President Dick Cheney's knowledge of the leak of a C.I.A. officer's identity. Representative Henry A. Waxman, Democrat of California and the chairman of the Government Oversight Committee, has said Attorney General Michael B. Mukasey should be held in contempt for refusing to provide the record of Mr. Cheney's interview with investigators regarding the leak of Valerie Wilson's name. Mr. Waxman described the invocation of executive privilege as ludicrous because the information sought did not involve any communication between the vice president and the president. Mr. Mukasey wrote to Mr. Bush earlier this week, saying executive privilege would be appropriate because ''I am greatly concerned about the chilling effect that compliance with the committee's subpoena would have on future White House deliberations.''